1. Technical Field
The present invention relates to optical-emission-signal output apparatuses for specifying optical-emission timings, for use in image display apparatuses and the like.
2. Related Art
FIG. 7 is a block diagram showing a conventional image display apparatus. The image display apparatus 100 includes an optical-emission unit 102 for outputting an optical beam 101 and an optical-scan unit 103 for scanning the optical beam 101 output from the optical-emission unit 102. The image display apparatus 100 is structured so as to display an image on the retina in an eye 104 of an observer, a screen, or the like, by means of the optical-scan unit 103 which scans the optical beam 101 on the retina in the eye 104, the screen, or the like.
The optical-emission unit 102 includes a video signal supply circuit 105, a light-source drive circuit 106, and a light source 107. The light-source drive circuit 106 drives the light source 107 in accordance with a video signal supplied from the video signal supply circuit 105, and the light source 107 outputs the optical beam 101 modulated by the video signal.
The optical-scan unit 103 has a horizontal scan block 108 and a vertical scan block 109. The horizontal scan block 108 scans light horizontally, as driven by a drive circuit 111. The vertical scan block 109 scans light vertically, as driven by a drive circuit 113. The drive circuit 111 drives a micromirror, provided as the horizontal scan block 108, so as to scan the optical beam 101 horizontally, in accordance with a horizontal synchronizing signal H supplied from the video signal supply circuit 105. The drive circuit 113 drives a galvanometer mirror, provided as the vertical scan block 109, so as to scan the optical beam 101 vertically, in accordance with a vertical synchronizing signal V supplied from the video signal supply circuit 105.